1. Field of the Invention:
This invention relates to improved structure for input-weighted multitap digital filters, which improved structure input-weighted filters are particularly suitable for image processing, in real time, scanned two-dimensional images, such as television images.
2. Description of the Prior Art:
Reference is made to co-pending U.S. Pat. No. 4,674,125 entitled "Real-Time Hierarchal Pyramid Signal Processing Apparatus"; issued June 16 1987 to C. R. Carlson, J. H. Arbeiter and R. F. Bessler; and assigned to RCA Corporation. This Carlson et al. patent discloses real-time hierarchal pyramid signal processing apparatus which employs pipe-line architecture for analyzing in delayed real time, inter alia, the two-dimensional spatial frequency spectrum of television images defined by a temporal video signal, and for synthesizing in delayed real time such a temporal video signal from the analyzed frequency spectrum thereof. In particular, the signal processing apparatus disclosed in this co-pending Carlson et al. application is capable of implementing an algorithm, developed by Dr. Peter J. Burt (hereinafter referred to as the "Burt Pyramid") by means which include many digital convolution filters, decimators, expanders, and interpolation filters, all operating on a stream of multibit (e.g., 8-bit) digital signal samples. In the past, the total amount of hardware required for the structure of such digital convolution filters, decimators, expanders and interpolation filters was quite large and, hence, relatively expensive.